# NFSD: Prevent client use-after-free during NFSv4.0 revoked-state cleanup

CVE record · `CVE-2026-89658`

- **Identifiers:** `CVE-2026-89658`
- **State:** Confirmed
- **Severity:** CVSS 9.8 Critical
- **Critical:** Yes: CVSS 9+
- **CNA:** Linux
- **Technologies:** [Linux kernel](https://agentprime.io/advisories/technology/linux-kernel.md)
- **Published:** 11 Sept 2026
- **Updated:** 19 Oct 2026
- **Reviewed by a person:** No

Published by the CVE Program (CNA: Linux) at 11 Sept 2026, 19:45 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it.

## Critical

Critical, because:

- CVSS score 9.8: 9.0 or more.

How we decide what’s critical: <https://agentprime.io/advisories/critical.md>

## Affected products, as the CNA wrote them

- Vendor: Linux. Product: Linux.
  - affected: `d688d8585e6bea5e4e37f7497feea93b6b0a469c to before 0ae0d2b5c5a1b39c0b3c15d96b32a5b0c583d519` (git)
  - affected: `d688d8585e6bea5e4e37f7497feea93b6b0a469c to before b413ec5b23e3445dc9c4f273116078e2d4747626` (git)
  - affected: `d688d8585e6bea5e4e37f7497feea93b6b0a469c to before 81cf7f1413862f87b078920c838460a6a88aa030` (git)
  - affected: `d688d8585e6bea5e4e37f7497feea93b6b0a469c to before 7b4f8a1586c42d3afc3c0ac779af2db7ab1a5c55` (git)
  - Other versions: unaffected
- Vendor: Linux. Product: Linux.
  - affected: `6.9`
  - unaffected: `before 6.9` (semver)
  - unaffected: `6.12.109 to 6.12.*, inclusive` (semver)
  - unaffected: `6.18.50 to 6.18.*, inclusive` (semver)
  - unaffected: `7.2.4 to 7.2.*, inclusive` (semver)
  - unaffected: `7.3 to *, inclusive` (original_commit_for_fix)
  - Other versions: affected

## Not analysed yet

We haven’t published our own analysis of this CVE. If a person reviews it, this page will say what’s affected and what has to be true for it to matter.

## Severity and exploitation

- 9.8 Critical, CVSS 3.1: `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`, from CNA (Linux)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0062, the 50th percentile, on 14 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

This record came from the full history of the CVE Program, published 11 Sept 2026. New records show when each source confirmed them.

## Sources

- [CVE List: CVE-2026-89658](https://www.cve.org/CVERecord?id=CVE-2026-89658)
- [NVD: CVE-2026-89658](https://nvd.nist.gov/vuln/detail/CVE-2026-89658)

### References from the CNA

- <https://git.kernel.org/stable/c/0ae0d2b5c5a1b39c0b3c15d96b32a5b0c583d519>
- <https://git.kernel.org/stable/c/b413ec5b23e3445dc9c4f273116078e2d4747626>
- <https://git.kernel.org/stable/c/81cf7f1413862f87b078920c838460a6a88aa030>
- <https://git.kernel.org/stable/c/7b4f8a1586c42d3afc3c0ac779af2db7ab1a5c55>

Facts on this page come from the CVE List as the CNA published them, with CVSS from the sources named above, CISA KEV and FIRST EPSS. Vendors, products and versions are shown as the CNA wrote them. We don’t reproduce the CVE’s description.

## Check whether this affects you

This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it. Compare the affected versions above with what you run.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), `get_advisory` returns this record and `search_advisories` finds related ones. Setup: <https://agentprime.io/mcp.md>
- As JSON: <https://api.agentprime.io/v1/advisories/CVE-2026-89658>
- Everything that needs attention now: <https://agentprime.io/advisories/critical.md>

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The web page: <https://agentprime.io/advisories/CVE-2026-89658/>. Everything for agents: <https://agentprime.io/llms.txt>.